Perforating gun with serial firing means



' Patented' sept. 3o, 1941 rEnFonATmG GUN wrrn saam mma MEANS 1ra J. McCullough, Los Angeles, cuir.

Application Febuary 1o, 1940, serial Na. 3111,297

(o1. isi-n.5)

12 Claims.

My invention relates to means for perforating casing while it is in place within a well, and relates'in particular to a gun perforator whereby the perfor-ation ofthe casing or casings is accomplished by firing projectiles therethrough.

It is an object of theinvention to provide a perforat'ing gun of simple character which may f be made small enough to pass through an oil tube set in a Well casing without sacrifice of operproducts produced from the burning of a charge of powder in a separate chamber and delivered to the 4chamber containing theexplosive throughY .a passage of relatively small diameter, which may be referred to as the ignition passage, a" particular feature of the invention being the provision of valve means which prevents reverse ow of gas through the ignition passage, thereby reducing to substantially minimum the loss ofpressure resulting Afrom the burning of the propelling charge of explosive associated with the gun bore.

AThe present invention contributes in the making of a perforating gun of relatively high efllciency but of relatively small diameter. As the diameter of the gun body is reduced, the dimension vof other of the parts must be likewise reduced, including the diameter of the powder chamber lwhich connects to the inner end of the gun bore. lThe size of this powder chamber places restrictions upon the quantity of explosive -which may be employed. My present invention makes it possible to obtain near to maximum Ipropelling effect from the gaseous combustion productgresulting from the, firing of a charge of given size.

It is a further object of the invention to provide a perforating gun of the character set forth venting reverse iiow of gas therethrough. Accordingly, the tiring of a charge in the first chamber of the gun results in the serial firing of all of the charges.

A further object is to provide a simple valve means of the character described placed so that it will vpermit passage of gas through an ignition passage into a chamber and will be effectively closed by pressure of gas in such chamber resulting from the tiring or burning' of the charge therein.

A further object of the invention is to provide a simple check or closure valve having associated means for urging it toward closed relation to a valve orifice forming a, part of the ignition vpassage of the gun.

Further objects and advantages of the invention will be brought out-in the following' part of the specication.

Referring to the drawing which is .for illustrative purposes only:

Fig. 1 is a view of a gun body sectioned on a medial plane, showing a preferred form of my invention. v

Fig. 2 is a. cross-section taken on the plane indicated by the line 2 -2 of Fig. 1.

Fig. 3 is an enlarged fragmentary cross-section showing a check or closure valve having a spring to urge the saine toward closed relation.

Fig. 4 is an enlarged vfragmentary sectionaly view of an alternative forrn` of valve wherein the closure member is yleldably held in engagement with the valve seat. t

Fig. 5 is lan enlarged fragmentary sectional Vview to show the space between the valve closure and seat of Fig. 1. 1 t

For the purpose of illustrating a simple embodiment wherein the invention may be piac-A ticed, I. have in Fig. 1 shown that portion of a gun body l0 with which the present invention is concerned. This gun body I0 includes a plurality of cylindrical sections Il which are arranged in consecutive order .below an yupper section I2 which may be formed and suspended froma cable in the general manner shown in my Patent No. 2,218,802, granted October 22, 1940, and my copending application Serial No. 304,333. It will be understood that the sections Il and I2 may be secured together in any suitable manner. Forconnecting these sections together in axial alignment I prefer to employ threaded tool joints, andV accordingly I have shown the sections Il each provided with a threaded box or tapered counterbore I3, at the upper end thereof, and have shown the sections II and I2 with cooperating downwardly extending threaded pins I4.

The body sections II are provided with gun bores I5 formed in barrels I6 which are threaded into bores I1 in the gun body Il. An elongated powder chamber I8 communicates with the inner end of each bore I1 and accordingly with the inner end of each gun bore I5. In each chamber I8 a suitable powder charge I9 is placed, and the gas pressure resulting from the combustion of the charges I9 is employed to discharge projectiles 2|) Vat high velocity from the gun bores I5. In the use of the term powder charge I intend the inclusion of all explosives suitable for use in the manner described. The powder charge chambers I8 are serially connected in such a manner that thecombustion or burning of a charge I9 in one of the chambers will result in the ring of the charge in the succeeding chamber of the series, whereby a serial firing of all of the powder charges will be accomplished.

The upper section I2 has a bore 2| leading downward from the upper end thereof, and extending downwardly from the bottom of the bore 2| there is a chamber or bore 22 to receive a priming cap or ilring cartridge 23. A firing pin 24 is supported for axial movement in the bore 2| by a. threaded bushing 25, the lower end of this iiring pin 24 having a head 26 from which a -point 21 projects downward for engagement with the head of the cartridge 23 when the iiring pin 24 is driven down. A removable valve seat member 28 may be secured in the lower end of each threaded pin I4, and an ignition passage 29 of relatively small diameter is extended down from the bore 22 through the pin I4 and through the valve seat 28.

In each body section II a valve chamber 30 is vformed in the bottom of each threaded box I3, to communicate with the upper end of each powder chamber |18. Each gun bodysection II has an ignition passage 3| which extends downward from the lower end of a powder chamber I8 and through a pin I4 and a valve seat member 28. To restrain the downward passage of gas therethrough,4 the passage 3| has at least a portion thereof, such as the upper section 32, made to small diameter.

In each valve chamber 30 I place a valve closure member 33 comprising a cylindrical body 34 having an upwardly projecting conical point 35 to engage a cooperating valve seat 36 formed in a valve seat member 28. The cylindrical member 34 has openings 31 extended from the upper to the lower end thereof, these openings being shown in the form of radial slots, the inner walls 38 of which converge downwardly. These slots 31 cooperate with other passages shown and described to form passage means connecting the chambers of the device which contain the lexplosives. For example, the upper bore 22 which receives the cartridge 23 constitutes a chamber for the explosive contained in the cartridge 23. Such 'chamber 23 is connected with the next downwardly consecutive powder chamber I8 by passage means consisting of the passage 29, the space 4U in the upper chamber 30 and the grooves or slots 31 of the cylindrical member 34. Adjacent powder chambers I3 are connected by passage means comprising a passage 3| and the space Within a valve chamber 3U not filled bythe contained closure member 33. The height of the closure member 33 is such that when it rests on the bottom wall of the chamber 30 in which it is contained, there will be, as shown in Fig. 5, a

small space or oriiice 35' between theA conical point 35 and the valve seat 36.

In the operation of the gun, with the cooperating parts assembled as shown in Fig. 1, the ring lpiri 24 is driven down to bring the point 21 into engagement with the cartridge 23. The combustion products from the cartridge 23 pass downwai'd through the passage 29 and around the valve closure member 33 into the upper powder chamber |8 to set off the charge |-9 in such chamber I8. The gaseous products from the burning of the charge I9 in the upper chamber I8 immediately produce a high pressure with the result that the upper valve closure member 35 is lifted into engagement with the seat 36. When the gas pressure in the upper chamber I8 reaches such high value as to shear off the plate 45 which holds the upper projectile 20 in its gun bore I5, the projectile will be discharged at high velocity. The upper valve, comprising the closure member 35 prevents the high pressure resulting from the 'relatively heavy charge I9 from passing up through the passage 29 and the bore 22 and exerting its force against the lower end of the firing pin 26, thereby relieving the firing pin 24 from danger of being bent by end thrust applied thereto.

Some of the gas produced in the upper chamber I8 as the result of the burning of a charge I9 therein pa'sses down through the passage 3| and past the valve closure member 33 lying at the lower end thereof, into the succeeding powder chamber I8, thereby causing ignition of the second charge I9. 'I'he second valve closure member 33 prevents a reverse ilow of gas from the second chamber I8 through the passage 3|, so that there can be no escape or loss of the products resulting from the firing of the second charge I8, thereby assuring that the full force of the products of the explosion of the second charge I9 will be usefully applied in discharging the second projectile 20 and transmitting the ignition eiect through the succeeding passage 3| to the succeeding powder chamber, which is not shown for lthe reason that it is merely a duplication of the powder chambers I8 shown and described.

In Fig. 3 I show a valve chamber 30 of essentially the same character and having the same position as the valve chamber 30 of Fig. 1, in which a valve closure member 33' is operatively disposed. This valve member 33 diiers from the valve member 33 previously described in having the lower portion 46 thereof reduced in diameter so as to leave an annular space 41 within the lower part of the chamber 30' below a shoulder 48 intermediate the ends of the valve closure member 33. For passage of gas from the upper end to the lower end of the chamber 30 the valve closure member 33' is provided with a plurality of openings 31' which are spaced around the conical valve projection 35 of the member 33. A spring 49 in the space 41 operates in compression to exert a yielding force in upward direction to hold the conical projection 35' in engagement with the valve seat 36'.

In Fig. 4 I show a form of my invention Wherein a conical valve closure 50 is formed in the center of a disc 5I which fits into a recess 52 formed in downwardly projecting relation in the bottom of a box I3 of a section Il. The bottom wall 53 of the disc 5I is recessed as shown so that only a peripheral area 54 of the bottom wall of the disc 5| will engage the bottom wall 55 of the recess 52. The conical closure member 50 is so formed with relation to the remaining portion of che disc that it wm be yieldably maintained in engagement with a valve seat 56 formed in a valve plate 51 which rests in the upper part of" thev recess 52 and is clamped in place by the lower end of a pin I4. A plurality of openings 58 are spaced around the closure member 50 for passage of gas downward into the upper part of a powder chamber I8 which extends downward from the recess 52 as shown. When an ignition gas is applied through an ignition passage, such as the passage 3|', the force thereof will move the closure member 50 downward,I since the central portion of the disc 5I is so formed that it may be flexed downward` when suiiicient pressure is applied, permitting the ignition gas to pass between the closure member 50 and the valve seat 56, and

thence through the opening 58 into the chamber a I8. When the gas pressure above and4 below the closure member 50 is equalized, the closure mem-- ber 50 will be returned to engagement with the valve seat 56 lby resilience of the disc 5I which tends to hold the closure member 50.111 the condition thereof shown in Fig. 4.

Although I have shown and described simple and practical forms of my invention, it will be understood that certain parts or elements thereof may be replaced by other equivalent parts or4 powder chambers and passage means serially connecting said chambers so that ignition will be transmitted serially from one chamber to another; a powder charge in each -of said chambers; means for setting off one of said powder charges; and check valves in said passage means to prevent reverse fiows of gas therethrough.

2. In a perforating gun of the character described, the combination of :la body having a gun bore, a powder charge chamber connected to said gun bore, and an ignition passage connected to said chamber; means for passing an ignition gas through said passage into said chamber; vand valve means associated with said passage for preventing -a reverse flow of gas therethrough.

3. In a -perforating gun of the character described, 'the combination of: a body having a gun bore, a powder chamber connected to said gun bore, a second powder chamber spaced from said first chamber, and an ignition gas passage connecting said first and second chambers; powder charges in said chambers; means for setting off the powder charge in the first of said chambers; and closure valve means associated with said passage for preventing a reverse flow of gas from said second chamber to said first chamber.

4. In a perforating gun of the Acharacter described, the combination of: a body having a gun bore, a powder chamber connected to said gun bore, a second powder chamber spaced from'said first chamber, and an ignition gas passage connecting said first and second chambers; powder chargesin said chambers; means for'setting oi the powder charge in one of said chambers, a portion of the gaseous products therefrom passing through said passage to set off the powder charge in the other of said chambers; and check valve means associated with said passage for preventing reverse flow of gas through said ignition gas passage.

5. In a scribed, the combination of: a vbody having serially arranged gun bores and cooperating chambers to 'receive powder charges; means to ignite a powder charge in at n.least one of said chambers: and walls formingl passages serially connecting said chambers through which ignition gas may pass consecutively from each of said chambers to the next; and check valve means for said passages operative to prevent reverse'flow of y ignition gas therethrough.

6. l.In a. perforating gun of the character described, the combination of a body having a gun bore, a first powder chamber connected toA said gun bore, a second powder chamber spaced from said first powder chamber, and passage means connecting said first and second chambers; a firing charge in each of said chambers: and valve means for said passage means for preventing r'e' verse flow of gas therethrough.

7. In a perforating gun of the character described. the combinationof: a body having a gun lbore, a first powder chamber connected to said gun bore,l a second powder chamber spaced from said first powder chamber, and passage means `connecting said first and second chambers; a firing charge in each of said chambers; and check valve means for saidpassage means comprising walls forming a valve orifice and a closure mem'- vber positioned so as to permit a forward fiowof gas from one of said chambers to the other of said chambers, and to close said orifice against a reverse flow of gas through said passage means.

8. In a perforating gun of the character described, the combination of: a body having a gun bore, a first powder chamber connected to said` v v valve means for said passage means comprising walls forming a valve orifice and a closure memfrom said first chamber toward said second chamber into closing relation to said orifice.

9. In` a perforating gun of the character described, the combination of: a body having a gun bore, a first powder chamber connected to said gun bore, a second powder chamber spaced from said first powder chamber, and passage m'eans Aconnecting said first and second chambers; a firing charge in each of said chambers; and check valve means for said passage means comprising a valve seat facing toward said rst chamber and dening an orifice forming a part of said passage.

means, a closure member to engage saidl valve seat, and means yieldably holding said vclosure member in engagement with said valve seat.

11. In a perforating gun of the character described, the combination of: a body having a perforating gun of the character de-y gun bore, a rst powder chamber connected to said gun bore, a second powder chamber spaced i'rom said'rst powder chamber, and passage means connecting said i'lrst and second chambers, said passage means including a valve chamber and a valve seat forming a valve orice at the end oi.' said valve chamber toward said second powder chamber; and a valve body movably disposed in said valve chamber so as to move to and from said valve seat, said valve body having a closure element to engage said valve seat and being so formed with relation to the walls of said valve chamber as to provide space for passage of gas from end to end of said valve chamber.

12. In a perforating' gun of the character described, the combination of: a body having a gun bore. a first powder chamber connected to said gun bore, a second powder chamber spaced -from said first `powder chamber, and passage means connecting said first and second chambers, said passage means including a valve chamber and a valve seat i'ormng a valve orifice at the end of said valve chamber toward said second powder chamber; and a valve body movably disposed in said valve chamber so as to move to and from said valve seat, said valve body having a closure element to engage said valve seat and having openings from end to end thereof for passage of gas freely from one end to the other of said valve chamber.

IRA J. MCCULLOUGH. 

